Carrying out heat treatment of springs
Overview
This standard identifies the competences you need to apply specified heat treatment processes to coil springs, wire forms or flat/strip springs, in accordance with approved procedures. You will be required to select and prepare the appropriate equipment to use, based on the heat treatment process to be carried out and the types of material to be treated. The heat treatment activities will include hardening, tempering, annealing and normalising, as applicable to the task.
Your responsibilities will require you to comply with organisational policy and procedures for the spring heat treatment activities undertaken, and to report any problems with the tools and equipment, materials or activities that you cannot personally resolve, or that are outside your permitted authority, to the relevant people. You will be expected to work with a minimum of supervision, taking personal responsibility for your own actions and for the quality and accuracy of the work that you carry out.
Your underpinning knowledge will provide a good understanding of your work, and will provide an informed approach to safely applying appropriate heat treatment processes for coil springs, wire forms or flat/strip springs. You will understand the heat treatment processes, the equipment used and its application, and will know about the materials and heat treatment techniques in adequate depth to provide a sound basis for carrying out the heat treatment activities to the required specification.
You will understand the safety precautions required when carrying out the heat treatment operations, and when working with heat treatment furnaces, quenching mediums and when using the associated tools and equipment. You will be required to demonstrate safe working practices throughout, and will understand your responsibility for taking the necessary safeguards to protect yourself and others in the workplace.
Performance criteria
You must be able to:
- work safely at all times, complying with health and safety legislation, regulations, directives and other relevant guidelines
- prepare the materials in readiness to receive the appropriate heat treatment
- check that the heat treatment equipment is set up and maintained at satisfactory operating conditions
- carry out the heat treatment process, using appropriate techniques and procedures
- check that the finished material achieves the required characteristics and meets the heat treatment specification
- deal promptly and effectively with problems within your control, and seek help and guidance from the relevant people if you have problems that you cannot resolve
- shut down the heat treatment equipment to a safe condition on completion of the activities
- leave the work area in a safe condition on completion of the heat treatment activities
Knowledge and Understanding
You need to know and understand:
- how to work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines
- the hazards associated with carrying out heat treatment processes and how to minimise them and reduce any risks
- the personal protective equipment (PPE) that should be used, how to obtain it and check that it is in a safe and usable condition
- the importance of ensuring that fume extraction equipment is operating effectively and that good housekeeping and fire prevention procedures are observed
- the importance of following job instructions and defined heat treatment procedures
- how to obtain the required information on heat treatment temperatures, soak times and quenching/cooling methods to be used
- the various types of spring material that can be flame hardened, case hardened, tempered, normalised and annealed
- the material preparation methods and techniques to be undertaken prior to applying the heat treatments (such as removing scale, oil and dirt; ensuring that springs are dry, have been pre-heated or are correctly masked up)
- the reasons for heat treating the springs
- the various heat treatment processes, methods and procedures that may be applied
- the basic principles of operation of the specific heat treatment process being carried out
- the types of equipment that can be used to carry out the various heat treatment processes
- how to prepare the equipment for the heat treatment activities
- the importance of making certain that all springs and jigs are completely free of water or other solvents prior to immersing them in a hot solution, and the potential consequences of failing to check this
- the methods used to hold/secure components in a heat treatment solution
- the importance of monitoring the equipment settings and solutions during the heat treatment process
- how to ensure that the components are heated to the correct temperature for the process being carried out and why these temperatures must be adhered to
- the various cooling and quenching techniques that are applied to the processes (including water, oil, sand, air, gas fan cooling), and why it is important to use the correct process
- the use of quenching oils, and the need to maintain the oil temperature below the oil flashpoint
- information sources on heat treatment temperatures, tempering colours, soak times required and quenching/cooling mediums to be used
- how to check the finished work after heat treatment
- the problems that can occur with the heat treatment operations, and how these can be overcome
- the importance of completing all relevant documentation on conclusion of the spring heat treatment activities
- the extent of your own responsibility and to whom you should report if you have problems that you cannot resolve